Dermacozine N, the First Natural Linear Pentacyclic Oxazinophenazine with UV-Vis Absorption Maxima in the Near Infrared Region, along with Dermacozines O and P Isolated from the Mariana Trench Sediment Strain MT 1.1.

Three dermacozines, dermacozines N-P (-), were isolated from the piezotolerant Actinomycete strain MT 1.1, which was isolated from a Mariana Trench sediment in 2006. Herein, we report the elucidation of their structures using a combination of 1D/2D NMR, LC-HRESI-MS, UV-Visible, and IR spectroscopy. Further confirmation of the structures was achieved through the analysis of data from density functional theory (DFT)-UV-Visible spectral calculations and statistical analysis such as two tailed -test, linear regression-, and multiple linear regression analysis applied to either solely experimental or to experimental and calculated C-NMR chemical shift data. Dermacozine N () bears a novel linear pentacyclic phenoxazine framework that has never been reported as a natural product. Dermacozine O () is a constitutional isomer of the known dermacozine F while dermacozine P () is 8-benzoyl-6-carbamoylphenazine-1-carboxylic acid. Dermacozine N () is unique among phenoxazines due to its near infrared (NIR) absorption maxima, which would make this compound an excellent candidate for research in biosensing chemistry, photodynamic therapy (PDT), opto-electronic applications, and metabolic mapping at the cellular level. Furthermore, dermacozine N () possesses weak cytotoxic activity against melanoma (A2058) and hepatocellular carcinoma cells (HepG2) with IC values of 51 and 38 μM, respectively.